Omron CJ - REFERENCE MANUAL 02-2010 Reference Manual page 260

3. Instructions
Function
• When the timer input is OFF, the timer specified by N is reset, i.e., the timer's PV is reset to the SV
and its Completion Flag is turned OFF.
• When the timer input goes from OFF to ON, TMHH(540)/TMHHX(552) starts decrementing the PV.
The PV will continue timing down as long as the timer input remains ON and the timer's Completion
Flag will be turned ON when the PV reaches 0000.
• The status of the timer's PV and Completion Flag will be maintained after the timer times out. To
restart the timer, the timer input must be turned OFF and then ON again or the timer's PV must be
changed to a non-zero value (by MOV(021), for example).
• The setting range for the set value (SV) is 0 to 9.999 s for TMHH(540) and 0 to 65.535 for
TMHHX(552).
• The timer accuracy is -0.001 to 0 s.
Note The timer accuracy for CS1D CPU Units is 10 ms + the cycle time.
The timer accuracy for CJ2 CPU Units and unit version 4.1 of the CJ1-H-R is -0.01 to 0 s.
Hint
The timer PV and timeup used in TMHH/TMHHX instructions are refreshed at the timing below.
*1
T0000 to T0015
Refresh timing
1) When each instruction is
executed
2) Refresh every 1 ms
*1 Cannot be used in CJ-H-R CPU Unit Version 4.1.
Precautions
• Timer numbers are shared with other timer instructions. If two timers share the same timer number,
but are not used simultaneously, a duplication error will be generated when the program is checked,
but the timers will operate normally. Timers which share the same timer number will not operate
properly if they are used simultaneously.
• The Completion Flag is updated only when TMHH(540)/TMHHX(552) is executed. The Completion
Flag can thus be delayed by up to one cycle time from the actual set value.
• The present value of a high-speed timer with a timer number from 0 to 15 will be refreshed even if the
task is on standby.
• Timers will be reset or paused in the following cases. (When a timer is reset, its PV is reset to the SV
and its Completion Flag is turned OFF.)
Condition
Operating mode changed from RUN or MONITOR mode
to PROGRAM mode or vice versa.
Power supply interrupted and reset
Execution of CNR(545)/CNRX(547), the RESET
TIMER/COUNTER instructions
Operation in interlocked program
section (IL(002)-ILC(003))
Operation in jumped program section
(JMP(004)-JME(005))
*1 If the IOM Hold Bit (A500.12) has been turned ON, the status of timer Completion Flags and PVs will be maintained when
the operating mode is changed.
*2 If the IOM Hold Bit (A500.12) has been turned ON and the status of the IOM Hold Bit itself is protected in the PLC Setup,
the status of timer Completion Flags and PVs will be maintained even when the power is interrupted.
*3 The PV will be set to the SV when TMHH(540)/TMHHX(552) is executed.
224
Description
The timeup flag is ON
when the PV is 0 and OFF
otherwise.
Refresh PV every 1 ms
*1
*2
*3
*2
T0016 to T4095
Refresh timing
When each instruction is
executed
*2 Only with a CJ1-H-R/CJ2 CPU Unit.
PV
0
0
BCD: 9999
Binary: FFFF
Reset to SV.
PV continues
decrementing.
CS/CJ/NSJ Series Instructions Reference Manual (W474)
Description
The timeup flag is ON
when the PV is 0 and OFF
otherwise.
Completion Flag
OFF
OFF
OFF
OFF
Retains previous
status.